Fractionating tower stripper construction



April 3, 1934. J. s. WALLIS FRACTIONATING TOWER STRIPPER CONSTRUCTION Filed Oct. 31, 1951 2 Sheets-Sheet l u u u n u u l I I i l I I I M fl. MM W3 V 5. NH M J m A TTORN E Y.

Patented Apr. 3, .1934 I UNITED STATES PATENT OFFICE FRACTIONATING TOWER STRIPPER CONSTRUCTION John S. Wallis, New York, N. Y., assignor to Alco Products, Incorporated, New York, N. Y., a corporationof Delaware Application October 31, 1931, Serial No. 572,302

2 Claims. (Cl. 196--139) My invention relates to a stripper construction tilized and the heavier fractions are withdrawn for stripping lighter fractions of petroleum hyfrom the stripper section and passed to overdrocarbons from a fractionating zone in a frachead cylinder storage, or refluxed back into the tionating tower, and more. particularly to a stripfractionating column in order to reduce the parper section which is built in and made integral tial pressure within the column, while the lighter 9 withafractionating tower. vapors are stripped and returned to the frac- It has lately become the practice to remove tionating zone.

side streams from a. fractionating column and More particularly, referring now to the drawstrip them of their low boiling constituents, which ings, Fig. 1 shows the usual fractionating column are present due to the equilibrium which is estab- 1 which may be of any suitable type, having the 5 lished between the liquid and the vapor in each usual connections 2, 3 and 4 for taking ofi side fractionating zone. When these lighter fracstreams, and the customary overhead 5 for retions are removed. it is possible to obtain oils moving the light fractions. Within the frachaving a higher flash point which are particutionating column are the usual fractionating larly adapted for use in making lubricating oils. zones which may be established by bubble trays One construction for stripping a side stream 6 or in any other suitable manner. The reduced in which the stripping section is disposed interhot crude enters the column through pipe 7, nally of the fractionating column is shown in whence it rises into a fractionating zone, as 8 for United States patent to John W. Lewis, Jr., No. example. Part of the reflux liquid within said 1,680,421. One disadvantage of the Lewis 0011- zone 8 will flow downwardly through pipe 9 into struction is that the heavy vapors rising in his the stripper section 10 which is divided into a central cylindrical portion can pass over into the plurality of zones. Steam enters through pipe stripping section. When this occurs condensa- 11 into the lower zone 12 of the stripper section. tion will take place of these heavy vapors and The action of the steam volatilizes the lighter 5 contaminate the side stream undergoing steam fractions and the vapors rise through bubble stripping. trays 13 and 14 and out through vapor riser 16 One object of my invention is to provide a coninto fractionating zone 8. The stripped side struction in which a steam stripping means is stream passes out of the stripper section 10 incorporated in a fractionating tower so that through the line 1''! where it may go to overhead there can be no contamination of the side stream cylinder stock or may form a reflux back into 35 undergoing steam stripping by the heavier vathe fractionating column. As many stripping pors. sections as may be convenient or desirable may Another object of my invention is to provide be installed in the various places in the fraca steam stripper section in which only condensate tionating column, depending upon the number 5 from one fractionating zone will form the reflux of lubricating oil stocks it is desired to take off.

passing through the stripper section. Thus it is seen that there is no danger of any Other objects of my invention will appear from condensate of vapors of the hot reduced crude enthe following description. tering the tower 1 from going directly into the Fig. 1 shows a diagrammatic view of a fracstripping section. tionating column embodying one mode of carry- Fig. 3 shows a modified structure embodied in ing out my invention. my invention in which the stripper section is an- Fig. 2 is a section taken on the line 2-2, Fig. 1. nular rather than segmental, as shown in the Fig. 3 is a view showing a portion of a fracmodification in Fig. 1. The action in this modi- I tionating tower embodying another mode of fication is precisely the same as that described 45 Carrying out y inVentiDnwith regard to the structure shown in Fig. 1.

4 is a SectiOn taken 11 the line In operation, hot reduced crude is introduced 3- into the fractionating column at any convenient In general, y invention contemplates the point. Fractionation takes place and the reflux v stablishm nt f a t pp ti with n th in zone 8 is split so that part of it passes into the 50' fractionating 6011111111 d having 110 m stripper section. Steam is introduced into the cation With the int m 0f t Column except stripper section to drive off the lighter ends of the through a single fractionating stage, f m Which fractions and the cylinder stock is withdrawn from a portion of the reflux liquid within said stage the tt of t stripper ection,

may p downwardly into the steam stripper It is seen that my construction accomplishes the section, wherein the lighter fractions are volaobjects of my invention. Iam enabled to produce a lubricating oil stock'which is free of contamination by any of the other fractions within the fractionating column. This will result in a lubricating oil stock of singularly uniform qualities. The discoloration due to contamination by heavy ends will be prevented.

It is to be understood that I do not wish to be limited to the particular form of construction shown and described, except insofar as appears in the following claims.

Having thus described my invention, what I claim is:

1. A fractionating column for processing petroleum hydrocarbons comprising in combination means to establish a plurality of fractionating sections, a stripper section within said column positioned below the lowest of said fractionating sections, and a hot oil inlet pipe to said column below said lowest fractionating section, said stripper section having means to communicate with said lowest fractionating section only, whereby a lubricating oil stock of uniform quality may be produced.

2. A fractionating column for use in the processing of petroleum hydrocarbons comprising in combination means to establish a plurality of frac tionating sections, a stripper section withingsaid from said bottom-most section into said stripper section and means for passing strippedvapor from 7 means including means for passing reflux liquid 7 the stripper section into the bottom-most fractionating section, and means for withdrawing stripped liquid reflux from the stripper section, whereby a lubricating oil stock of uniform quality may be produced. JOHN S. WALLIS. 

